Title of Paper:Hybrid Beamforming With Dynamic Subarrays and Low-Resolution PSs for mmWave MU-MISO Systems

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Date of Publication:2020-01-01

Journal:IEEE TRANSACTIONS ON COMMUNICATIONS

Included Journals:EI、SCIE

Volume:68

Issue:1

Page Number:602-614

ISSN No.:0090-6778

Key Words:Array signal processing; Radio frequency; Antenna arrays; Hardware; Transmitting antennas; Heuristic algorithms; Millimeter wave (mmWave) communications; hybrid beamforming; dynamic subarrays; low-resolution phase shifters (PSs); multiple-input single-output (MISO)

Abstract:Analog/digital hybrid beamforming architectures with large-scale antenna arrays have been widely considered in millimeter wave (mmWave) communication systems because they can address the tradeoff between performance and hardware efficiency compared with traditional fully-digital beamforming. Most of the prior work on hybrid beamforming focused on fully-connected architecture or partially-connected scheme with fixed-subarrays, in which the analog beamformers are usually realized by infinite-resolution phase shifters (PSs). In this paper, we introduce a novel hybrid beamforming architecture with dynamic subarrays and hardware-efficient low-resolution PSs for mmWave multiuser multiple-input single-output (MU-MISO) systems. By dynamically connecting each RF chain to a non-overlap subarray via a switch network and PSs, we can exploit multiple-antenna and multiuser diversities to mitigate the performance loss due to the use of practical low-resolution PSs. An iterative hybrid beamformer design algorithm is first proposed based on fractional programming (FP), aiming at maximizing the sum-rate performance of the MU-MISO system. In an effort to reduce the complexity, we also present a simple heuristic hybrid beamformer design algorithm for the dynamic subarray scheme. Extensive simulation results demonstrate the advantages of the proposed hybrid beamforming architecture with dynamic subarrays and low-resolution PSs compared to existing fixed-subarray schemes.